The Right To Bear Salt: Is Sodium Restriction Warranted For The General Population?
Q. What is the difference between a public health expert and Il Duce?
A. Mussolini was not nearly as arrogant as a public health expert.
In prior posts, DrRich related how two major publc health efforts over the past few decades – the effort to put all of us on low-fat diets, and the effort to reduce everyone’s cholesterol levels – have amounted to massive experiments, based upon insufficiently-tested assumptions and surmises and hypotheses which the experts arrogantly (and incorrectly) determined to be fact, and which were conducted upon the entire American population without its knowledge or consent.
These public health experiments cost billions of dollars, needlessly transformed large swatches of American industry, and (at least in the case of low-fat diets) likely produced significant harm to the citizenry. Furthermore, despite such results, these misbegotten public health efforts have inured Americans to the notion that it is right and proper for government experts to determine for each of us what we must and must not eat.
DrRich now feels obligated to call his readers’ attention to yet another experiment which these same public health experts have launched, an experiment under which each of us – once again – is to become an unwitting research subject, an experiment whose results are unpredictable, but which has a realistic chance of producing harm to many of us. DrRich speaks, of course, of the new US dietary guidelines, published earlier this year, regarding sodium.
Those new guidelines begin with these established “facts:” Sodium is bad. We all get too much of it. And if we restricted our salt intake to a much lower amount than we are likely getting today, we will all become healthier and live longer. Relying on this received wisdom, the new guidelines call for us to cut back to 2300 mg of sodium per day – unless we are 51 or older, or African-American, or hypertensive (and most Americans fall into one of these three categories), in which case we are to restrict our sodium to 1500 mg per day.
For anyone who strays from eating only fresh fruits and vegetables, this kind of restriction is likely to prove a challenge. A nice bowl of dry cereal, for instance, even before you add milk, may give you up to 1000 mg of sodium.
Some Americans might consider such severe restrictions to be merely a statement of an ideal – a goal that, while laudatory, is entirely unreasonable or impracticable, one which we ought not expect to achieve with any degree of perfection, across a large population, in real life. But DrRich assures his readers that this is not at all how the Feds are viewing the matter.
The Institute of Medicine, for instance, is all over it. The IOM recently published (in conjunction with the new Guidelines) its “Strategies To Reduce Sodium Intake In the US.” Noting that public health experts have tried in vain for decades to get Americans to cut back on salt, the IOM says the time for persuasion by education has passed. The great unwashed are proved to be recalcitrant, yet again, to reason and science. It’s time to take the gloves off. So the IOM calls for the US government (specifically, the FDA) to use its regulatory firepower to enforce – once and for all – the kind of sodium restriction that the public welfare demands.
Specifically, the IOM calls for the FDA to reclassify “salt” from a food ingredient categorized as GRAS (“generally regarded as safe,” i.e., items which have been used for millennia in food preparation without regulatory oversight, such as pepper, parsley, or vinegar, and which are accepted as being harmless), to a “food additive” (i.e., a substance which is certifiably harmful, and for which strict, enforceable rules must be promulgated regarding its use). Re-classifying salt as a food additive will give the FDA the authority it needs to enforce its usage (as with any other regulated substance) in the food processing industry, in restaurants, and even, one must assume, in the home. With this new designation, the FDA (and other government agencies) will be able to deploy whatever regulatory and enforcement muscle they must, in order to assure that the Guidelines for sodium are at last realized.
This is serious stuff. The government at last seems dedicated, as never before, to actually implementing a significant sodium restriction for all of us within the teeming masses. All, of course, for our own good.
You might think, if you have not been paying attention, that in order for the Feds to launch into such a concerted, sustained, and widespread public health effort, the scientific data to support such an action must be pretty airtight. But if you have been paying attention, you will not be surprised to hear that the actual advisability of restricting dietary sodium across the entire population is anything but settled. In fact, it remains very controversial among scientists.*
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*DrRich stresses here that this discussion refers only to sodium restriction applied across the population. Sodium restriction for at least some people who already have hypertension – or a few other medical conditions such as heart failure and some types of liver and kidney disease – is well-established as being beneficial.
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There are at least three outstanding questions regarding the advisability of a general policy enforcing salt restriction. Until these questions are addressed, the implementation of a generalized and severe sodium restriction across the population seems to DrRich to be quite ill-advised (and, of course, incredibly arrogant).
1) Does Sodium Restriction Really Do Any Good?
DrRich could write several very long posts addressing just this one question. Instead, he will simply summarize the problem.
The question hinges on the relationship of salt intake to blood pressure – that is, does higher salt intake cause the blood pressure to increase? This turns out to be a difficult question to answer with any scientific precision. The studies are difficult to conduct, and difficult to interpret. Accurately measuring sodium intake in any sizeable population of patients is nearly impossible; and even measuring blood pressure (which varies tremendously from minute to minute, depending on activity, stress, and many other factors) in a reproducible way within a population of patients is difficult.
Scores of studies have been conducted to try to address this question. And one can assemble from these studies a large group which will show that salt intake correlates nicely with blood pressure. On the other hand, one can also assemble from these studies a large group that shows it does not. And for decades, the salt vs. blood pressure question has been divided into two camps, each of which have major conflicts of interest*, and which cite only those studies which tend to support their point of view.
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* In one camp are the National Heart, Lung, and Blood Institute, the National High Blood Pressure Education Program, the Institute of Medicine, and academic experts on hypertension whose careers have been based on funding from these organizations, and whose reputations and academic standing rely on sodium intake being a major determinant of blood pressure and health. In the other camp are the Salt Institute, the big manufacturers of processed foods, and sundry academic experts on hypertension whose careers have enjoyed funding from these sources. Take your pick.
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To see just how deeply politics is involved in the salt controversy, DrRich highly recommends this article by Gary Taubes, which appeared several years ago in Science, outlining the machinations that have been employed by the various parties in interpreting some of the complex studies that have attempted to correlate salt intake with blood pressure.
DrRich is convinced that, at the very least, this is not a settled question.
But even if it were a settled question, and sodium intake did indeed correlate nicely with blood pressure across the whole population (which, at a minimum, would be a necessary conclusion in order to legitimately enforce a sodium restriction across the whole population), the degree of blood pressure reduction that even sodium-restriction-enthusiasts predict, even employing very significant salt restrictions, seems trivial – most experts predict an reduction in blood pressure of only 1-2 mmHg. Assertions that public health experts often make to defend their sodium restriction guidelines, to the effect that this kind of tiny reduction in blood pressure on a worldwide basis would save over 100,000 lives per year, is (scientifically speaking) hogwash. Such estimates are calculated from strings of assumptions piled upon assumptions, and have little or no bearing on reality.
The fact is that we just don’t know what effect it would have on the population’s health to significantly restrict salt intake in everybody. We don’t know either the magnitude of blood pressure reduction it would achieve, or the improvement in clinical outcomes that would follow such blood pressure reduction.
We could find out if we really wanted to – by doing a large, randomized clinical trial to test the hypothesis. But the public health experts have determined that such a randomized trial is not necessary (the issue being “settled”), and not desirable (time being of the essence).
They would rather conduct a non-randomized experiment that enrolls every living American as an unwitting research subject. Then, in a couple of decades (reminiscent of the low-fat diet “experiment”), maybe we could figure out how it all worked out.
2) Does Sodium Restriction Cause Harm?
Here is a question that the public health experts, who consider salt restriction to be an unalloyed good, really object to. They tend to get downright nasty when anyone brings it up.
But, as it happens, it is a legitimate question.
Sodium is an extremely critical substance in any living creature. For any living cell to function normally, it must exist in an environment that contains, within a narrow range, just the right concentration of sodium. Consequently, living beings have evolved a complex series of mechanisms to assure an adequate sodium concentration under any and all circumstances. So, if animals are made to survive on a severely sodium-restricted diet, these homeostatic mechanisms are called into play to severely restrict the loss of sodium from the body. Such mechanisms can have many secondary effects.
In states of sodium depletion, tissues are more susceptible to injury from ischemia (lack of oxygen), a condition seen in heart attacks and strokes. Kidney damage caused by many types of medication will occur much more readily in states of sodium depletion. The way the kidneys handle various drugs is also altered when sodium intake is reduced, leading to potentially harmful changes in the blood concentrations of certain medications. The renin-aldosterone system is activated under salt restriction, which can have several adverse effects. (In fact, a major therapy for several medical conditions, such as heart failure and – ironically – hypertension, centers around suppressing the renin-aldosterone system.) Adrenaline levels and LDL cholesterol are increased when sodium is restricted. And at least one study, disturbingly, has correlated sodium restriction with an increase in cardiovascular mortality.
Calling attention to these kinds of findings just makes the sodium-restriction camp angry, and they usually respond by pointing out that so-and-so got a grant from the Salt Institute. (DrRich agrees that there are conflicts of interest, but those conflicts are flagrant on both sides.)
The fact is that the scores of observational trials that have been conducted do not allow anyone to reach a definitive conclusion about the advisability – regarding either its efficacy or its safety – of salt restriction across the population. An objective observer, operating on established scientific principles, would have to say that the only action that makes any sense at this point would be to conduct that large, randomized clinical trial, using actual clinical outcomes as an endpoint. Only such a trial can begin to sort out the discrepancies, and has any chance of allowing us to resolve the differences (by any means other than by fiat).
The public health experts, however, hold the high ground. That is, they control the “opinion” of the various health-related agencies wielded by the Central Authority. And they fail to recognize any discrepancies whatsoever. For them, the issue is settled, and it is past time to sweep aside any opposition, and implement the plan. Proponents of salt restriction have the will and they have the authority, and accordingly they have determined: Just do it.
3) Is It Even Possible To Change Sodium Intake By Public Policy?
Again, maintaining the proper sodium concentration in tissues is critical to life, so living creatures have evolved a complexity of mechanisms to assure that the concentration of sodium remains within the proper range.
Among these, it now appears, is an inherent “sodium appetite” enjoyed by all humans and all animals, an in-born mechanism that holds the body’s sodium content to a certain set-point, and determines how much sodium an individual will ingest each day to keep to that set-point. This set-point is maintained by a complex neural network involving several centers within the central nervous system, as well as inputs from the peripheral tissues. One’s physiology regulates one’s sodium intake to satisfy the body’s needs.
Furthermore, studies of sodium intake across a wide array of human populations, living under a wide variety of conditions and dietary constraints, also show that the range of salt consumption humans take in to achieve their set-point is remarkably universal, and is maintained within a fairly narrow range. That is, not only do humans consume the proper amount of sodium as determined by the body’s needs, but across the diversity of humanity that “automatic” sodium intake is maintained within a remarkably fixed range. (Sodium intake moves within that range to maintain the body’s proper sodium set-point.)
As it happens, the lower limit of that universal, naturally occurring, “optimal” range of sodium intake is roughly 2300 mg/day.
Astoundingly, this natural lower limit, determined by our physiology, is the same as the the upper limit our government would have many Americans consume. And our natural lower limit is far higher than the 1500 mg/day upper limit our government will be enforcing for more than half of us.
In other words, by decree, our government would have every American consume an amount of sodium that is below the optimal range as determined by human physiology. Almost by definition, anyone living under the recommended guidelines would likely be unable to maintain proper sodium concentrations through sodium intake alone, and would need to recruit the secondary, sodium-retaining, potentially-harmful physiological mechanisms (such as the renin-aldosterone system) to keep sodium concentrations at an adequate level.
In any case, it is apparent that even if a universally-applied policy of significant sodium restriction was proved to be safe and effective, it is not at all clear that it is possible to make people comply with such a restriction. This kind of restriction will be fighting our inherent “sodium appetite” regulator that has been forged through millions of years of evolution. This kind of restriction would appear to fly in the face of our human physiology.
We need salt, dear readers, we truly do. The only reason the Founders did not include an additional paragraph in the Second Amendment (to the effect that, “A palatable diet being necessary to the health and well-being of a free People, the right of the People to bear salt shall not be infringed,”) is that it never occurred to them that any government would ever attempt to restrict such an inherent physiological necessity.
Of course, anyone who has observed our government at work – as it attempts to implement policies that require a fundamental change in human nature, or that require the repeal of the basic laws of economics – should not be surprised at the notion that our Progressive leaders would also try to repeal human physiology.
I mean, why the heck not?
*This blog post was originally published at The Covert Rationing Blog*
In the UK we’ve been told not to take in more than 6gm per day . Nobody has said where they got that amount from .
Wow, Jim – that sounds like a lot (it’s almost 2.5x the US recommendations?) I personally don’t worry too much about salt in people with normal blood pressure. It make you retain water a bit… but so what? It goes away easily enough.